• Bulletin of the Korean Chemical Society
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• v.18 no.5
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• pp.488-495
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• 1997

The stability of bridgehead olefins containing 8 and 10 membered rings has been investigated by the MMX molecular mechanics calculation together with the GMMX conformational searching program. A number of 'hyperstable' bridgehead olefins, which have negative olefin strain values, have been found from the calculated values of strain energy and olefin strain for the series of in- and out-bicyclo[n.3.3]alk-1-ene and in- and out-bicyclo[n.4.4]alk-1-ene (n=1 to 8). For the bridgehead olefins with 'out' topology, hyperstable olefins were found in the systems having cyclononene or larger rings. For the bridgehead olefins with 'in' topology, hyperstable olefins were found in the systems having cyclodecene or larger rings.

• Bulletin of the Korean Chemical Society
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• v.15 no.11
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• pp.957-961
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• 1994

Epoxidation of olefins catalyzed by iron-tetraarylporphyrins were studied to see the shape selectivity in the competing reaction between cis-and trans- or internal and external olefins. Cis-olefins were more reactive than trans-olefins in the competing reaction between cis-and trans-olefins. Interestingly, in the epoxidation of $cis-{\beta}-methystyrene$ by ${\alpha}{\beta}{\alpha}{\beta}$ atropisomer of Fe(III)TNPPPCl and iodosylbenzene, 27% of total product was phenylacetone. The unusually large amount of phenylacetone may be produced by hydride rearrangement of carbocationic intermediate. Regioselectivity of the reaction was also studied by using the most sterically hindered Fe(III)TTPPPCl. In the epoxidation of limonene with Fe(III)TTPPPCl, the disubstituted double bond was more reactive than trisubstituted double bond. This is in contrast to the results obtained with other iron-tetraarylporphyrins. Similar trend was also observed in the competing reaction between mono-and di-substituted olefins.

• Bulletin of the Korean Chemical Society
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• v.14 no.4
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• pp.506-510
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• 1993

Irradiation of 1,4-diphenylbutadiyne (DPB) with a mixture of electron-deficient and electron-rich olefins in deaerated tetrahydrofuran yields a 1 : 1 primary photoadduct between DPB and electron-deficient olefins. Irradiation of the primary photoadduct of DPB and dimethyl fumarate (DMFu) with various olefins such as DMFu, acrylonitrile (AN), and 2,3-dimethyl-2-butene (DMB) in deaerated tetrahydrofuran yields regiospecific 1 : 1 photoadducts. The electron-deficient olefins are more reactive than electron-rich olefins in the photoreaction which proceeds through excited triplet state.

• Korean Chemical Engineering Research
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• v.58 no.1
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• pp.69-83
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• 2020

Light olefins are important petrochemicals as well as primary building blocks for various chemical intermediates. As the number of ethane cracking center (ECC) process, in which ethylene accounts for most of the production, has increased in recent years, propylene supply is not catching up with steadily increasing propylene demand. This trend makes the conversion of methanol to olefins to get more industrial importance. The methanol to olefins (MTO) process produces methanol through syngas and obtain olefins such as propylene through methanol. Since the reaction from methanol to olefins provides different product compositions depending on the catalyst used for the reaction, it is important to choose an appropriate separation process for the reaction product with different composition. Four different separation processes are considered for four representative cases of product compositions. The separation processes for the reaction products are evaluated by techno-economic analysis based on the simulation results using Aspen plus. Guidelines are provided for selecting a suitable separation process for each of representative case of product compositions in the MTO process.

• Korean Chemical Engineering Research
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• v.44 no.4
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• pp.345-349
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• 2006

Conversion of DME (dimethyl ether) or methanol to light olefins (ethylene, propylene, butenes) over SAPO-34 were systematically studied, where it was observed that DME was dehydrated to light olefins and partially converted to by-products such as CO and $CO_2$ at various reaction temperatures on the time-on-stream. SAPO-34 catalyst during the DTO (dimetyl ether-to-olefins) reaction was significantly deactivated compared with MTO (methanol-toolefins) reaction. By addition of water to the reaction feed, the yield to light olefins was not only increased, but the life time of the catalyst was also prolonged by the suppression of the coke formation by steam.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2642-2646
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• 2012

Pretreatment of spent FCC catalyst and its application in remove trace olefins in aromatics were investigated in this research. The most effective pretreatment route of spent FCC catalyst was calcining at $700^{\circ}C$ for 1 h, washing with 5% oxalic acid solution in ultrasonic reactor and dried. Treated spent FCC catalyst was modified with metal halides, then to prepare catalyst to remove trace olefins in aromatics. X-ray diffraction, Pyridine-FTIR, $N_2$ adsorption-desorption and inductively coupled plasma optical emission spectrometer (ICP-OES) were used to investigate the pretreatment process. The result showed that the performance of the treated spent FCC catalyst was much greater than that of the spent FCC catalyst, which indicted the possibility and improvement of this research.

• Bulletin of the Korean Chemical Society
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• v.25 no.9
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• pp.1305-1306
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• 2004

• Archives of Pharmacal Research
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• v.18 no.3
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• pp.213-214
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• 1995

Six new indeno[3,2-b]pyridine derivatives were synthesized via reactions of 1-phenylamino-3-indenone with cyano olefins.

• Bulletin of the Korean Chemical Society
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• v.8 no.1
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• pp.27-30
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• 1987

Photocycloaddition of 1,4,5,8-tetraazaphenanthrene to olefins proceeds through a biradical triplet-state intermediate as proven by the photoproduct stereochemistry, quantum yield measurements, sensitization, quenching, and fluorescence and phosphorescence quenching studies.

• Korean Chemical Engineering Research
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• v.44 no.4
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• pp.329-339
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• 2006

The production of lower olefins from methanol becomes an attractive process because of the rapid increase in crude oil price. This paper reivews the conversion mechanisms of methanol to hydrocarbons over zeolite and SAPO molecular sieve catalysts to understand the formation steps of lower olefins from methanol. The feasibility of the conversion mechanisms such as the direct mechanism based on well-defined intermediates and the hydrocarbon pool mechanism involving hydrocarbon moieties as an active centers is discussed with reepect to the induction period, the selectivity for products and the deactivation phenomena of the methanol conversion. The literature appeered since 1999 for the structure of the hydrocarbon pool and its catalytic role in the methanol conversion are summariged, and the prospect for the methanol-to-olefins process is described.